By Brian Rowan
BBC Northern Ireland security editor
The decommissioning men will emerge on Monday to tell us of the secret work they have been involved in over the past few weeks.
The men on this latest Irish mission are General John de Chastelain, Andrew Sens and Tauno Nieminen - the commissioners of the Independent International Commission on Decommissioning.
Statements are expected on IRA arms
Their job has been to put the IRA's weapons "beyond use", and confirmation is now imminent.
That confirmation will also come from new independent church witnesses - the priest Father Alex Reid and the former President of the Methodist Church, the Reverend Harold Good.
The commissioners and the churchmen will speak at a news conference at a hotel outside Belfast on Monday afternoon.
This is the follow-up to the IRA statement of July when it ordered an end to its armed campaign and said it would complete the decommissioning process.
There won't be the photographs demanded by Ian Paisley's Democratic Unionist Party last year, and the DUP-nominated church witness - the Reverend David McGaughey - was not involved.
But when de Chastelain and his colleagues tell the story of decommissioning, it will be different from anything we have heard before. It has to be.
This time it has to be "definitive", one source told the BBC News website.
The general has to be able "to account for all the weapons that he knows about", he added.
Another source says the general's message will be "clear" and we are expecting, if not an inventory, a more detailed description of the weaponry that has been dealt with.
This time the IICD will be able to say that the job of IRA decommissioning is now done - that they have put beyond use all the weapons the republican organisation has hidden in its arms dumps.
The commissioners have been working with security estimates of the scale of the IRA's arsenal - much of it Libyan-supplied, including the potent explosive Semtex.
So we are now expecting a detailed IICD account of what has happened over the past few weeks and that additional commentary from the two churchmen.
Peter Robinson said the IRA move had to be "convincing"
These are the new watching eyes, and what they have to say will be an important part of convincing a listening and watching public that the threat of the IRA's gun has now gone.
Some believe the DUP is positioning itself to "reject" whatever is said on decommissioning, and there is a belief that the party will use the fact there are no photographs and that their witness was not chosen, to dismiss what is said and done.
The deputy leader of the DUP, Peter Robinson, puts it differently.
"I absolutely cannot understand their (the IRA's) logic," he said. "This is the sort of thing you can't do twice. If it doesn't convince us, there will be long delays (in terms of re-building the political process).
"The key is, it's got to be convincing if it's going to build confidence in the unionist community. And it's obvious their priority is international opinion rather than unionist confidence."
One source dismissed the fact that the Mr McGaughey has not been involved saying: "It doesn't really matter (so long as) it's somebody who has mainstream unionist approval."
As the story of decommissioning plays out over the next 24 hours, there will be a statement from the IRA and a Belfast news conference at which the Sinn Fein President Gerry Adams will give his response.
This could be the last time that "P O'Neill" speaks in this IRA campaign.
The focus will switch soon to the business of loyalist decommissioning.
It has been their guns that have been loudest recently, and not one weapon has been decommissioned by the main organisations - the Ulster Volunteer Force and the Ulster Defence Association.
This is the next phase of work for the decommissioning body.